2018 Winter-in-review and Spring Outlook

Where are you?

Weather or Climate

The difference between weather and climate is dependent on time. To understand climate at a given place requires looking at weather over relatively long periods of time. Weather is the day-to-day interaction of factors like temperature, humidity, precipitation, cloudiness, visibility, and wind. In addition to studying weather, scientists examine climate trends or cycles of variability to understand the bigger picture of long-term changes.

In a Word…

Winter 2017: Season in review

La Nina didn’t dissappoint! Reflecting on last winter…

Temperature

  • In January–February, 2018, the average temperature statewide was 21.9 ºF, 1.4 degrees lower than the 1981–2010 normal value.
  • January–February, 2018 was the 82nd coldest winter since record keeping began in 1895.

Precipitation

  • In January–February, 2018, the average total precipitation statewide was 1.2 inches, 0.9 inches lower than the 1981–2010 normal value.
  • January–February, 2018 was the 5th driest winter since record keeping began in 1895.

Snowpack

Big Story: Blackfeet Blizzard

Soil Moisture

Snow and soil moisture recharge

“Recharge rates” …

Drought

Not out of it yet in the northeast.

ENSO: Moving towards neutral

Sea surface temperatures have remained below average, maintaining La Niña conditions in the ocean and lower atmosphere. Most models agree that as this winter transitions into spring, sea surface temperatures are expected to return to near average. Returning to ENSO-neutral in spring means neither El Niño nor La Niña conditions are present. When ENSO-neutral occurs, ocean and atmospheric conditions are near the long-term average and it often coincides with a transition from La Niña to El Niño or vice versa. While ENSO-neutral persists there is often less confidence in summer forecast as durations of neutral conditions vary. As this transition occurs, La Niña conditions will continue with below-average temperatures and above-median precipitation in spring for Montana. These conditions will gradually weaken and transition to neutral as spring transitions to summer.

Temperature

Precipitation

Spring 2018: Forecast

Temperature

TODO: Convert to 2-category system (1-(t+50)) (rescaled to 1)

Precipitation

Drought

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## Simple feature collection with 3 features and 4 fields
## geometry type:  POLYGON
## dimension:      XY
## bbox:           xmin: 595911 ymin: 276825.2 xmax: 1017293 ymax: 541731.5
## epsg (SRID):    102300
## proj4string:    +proj=lcc +lat_1=45 +lat_2=49 +lat_0=44.25 +lon_0=-109.5 +x_0=600000 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
##   Fcst_Date Target ORIG_FID              Drought Outlook
## 1 2/15/2018 May 31        0 Drought remains but improves
## 2 2/15/2018 May 31        0             Drought persists
## 3 2/15/2018 May 31        0       Drought removal likely
##                         geometry
## 1 POLYGON ((949113.5 538405.8...
## 2 POLYGON ((1007538 420059.1,...
## 3 POLYGON ((876837.4 410866, ...
## 
## $map

Winter 2040–2069: Outlook

Temperature

Precipitation

Snowpack

Comparison with Jan-Mar 2018

  • Temperatures across the state are predicted to be an average of 31 ºF, or 4.9 degrees above normal, and 9.2 degrees above winter 2018 temperatures.
  • Precipitation across the state is predicted to be an average of 3.5 in., or 0.3 in. less than normal, and 2.4 in. more than winter 2018 precipitation.

Planting 2018: What this all means

About Montana Drought and Climate and the Montana Climate Office